Hydraulically powered portable lifting apparatus



p 20, 1966 J. L. BRUNTON 3,273,721

HYDRAULIGALLY POWERED PORTABLE LIFTING APPARATUS Filed Jan. 15, 1965ITTR/VE/if United States Patent Ofiice 3,273,721 Patented Sept. 20, 19663,273,721 HYDRAULICALLY POWERED PORTABLE LlFTlNG AP?ARATUS James L.Brunton, 20924 Avis Ave, Torrance, Calif. Filed Jan. 15, 1965, Ser. No.425,816

1 Claim. (Cl. 212-35) This invention relates generally to liftingapparatus and more particularly to such apparatus which is portable andwhich is powered by fluid under pressure.

In the prior art, portable lifting apparatus such as portable cranes,have been designed and are used in many different applications. However,such prior art portable cranes have for the most part included a staticor dead line and have accomplished manipulation of the load throughmoving the boom of the cane. In some instances, however, where a liveline, that is, where the line moves with respect to the boom, has beenrequired, a manually operated boat type winch has been used both for thestorage of cable and at the same time for the power to move the line. Ineach instance the portable crane has been exeessively heavy and the loadwhich can be lifted by the portable crane is extremely limited, and thusthe utility of the crane is restricted.

Accordingly, it is an object of the present invention to pnovide aportable lifting apparatus such as a hydraulically powered portablecrane which utilizes a live line, which is relatively light in weight,and which has a substantially greater lifting capacity than presentlyknown prior art portable cranes.

It is another object of the present invention to provide a portablelifting apparatus which is substantially selfcontained, is rugged,exceedingly compact, and relatively inexpensive as compared to prior artportable cranes.

Other and more specific objects and advantages of the present inventionboth as to its construction and method of operation, will becomeapparent from a consideration of the following description taken inconjunction with the accompanying drawing which is presented by way ofexample only, and is not intended as a limitation upon the scope of theinvention as defined in the appended claims, and in which:

FIG. 1 is a side elevational view of a portable lifting apparatus inaccordance with the present invention;

FIG. 2 is a partial view of the boom of a portable lifting apparatus inaccordance with the present invention, having one side thereof removed;

FIG. 3 is a top elevati-onal view taken along the lines 3-3 of FIG. 1;and

FIG. 4 is a partial end view of the apparatus illustrated in FIG. 1taken along the lines 44 thereof.

A portable lifting apparatus in accordance with the present inventionincludes a boom carrying a cable and having a fluid pressure actuatoraflixed thereto. First pulley means is secured to the boom and secondpulley means is secured to the fluid pressure actuator, and is movablewith respect to the first pulley means. The cable engages the pulleymeans and has one free end which can be used to engage loads and whichmoves as the actuator moves when fluid under pressure is appliedthereto.

In accordance with a more specific aspect of the present invention, thehydraulically powered portable lifting apparatus in accordance with thepresent invention, has a boom carrying a cable and includes a hydraulicactuator which is aflixed to the boom. The hydraulic actuator in turnincludes a cylinder and a movable piston which has a shaft securedthereto and extending through one end of the cylinder. A pair of pulleysis afiixed at one end of the boom, and another pair of pulleys isaffixed at the terminal end of the shaft and is movable therewith. Thecable engages the pulleys and has one end fixed and the other end freeand extending from the boom for engaging loads. Means is pnovided formaintaining the pairs of pulleys is a predetermined aligned relationshipwith the boom. Upon application of fluid under pressure to the actuator,the pulleys aflixed to the shaft move, thus causing the free end of thecable to move permitting lifting or other manipulation of the load.

Referring now to the drawing and more particularly to FIGS. 1 through 4thereof, the portable lifting appara tus or crane is illustratedgenerally at 10, and includes a post member .11 and a boom member 12.The boom member 12 is pivotally secured to the post 11 as by means of apivot pin '13. A boom lift hydraulic actuator 14 includes a cylinder 15,and a movable shaft or ram 16, operatively associated with the cylinder15. The cylinder 15 is pivotally aflixed as by the pin 17 at one endthereof, to a collar 18 rigidly attached to the post 11. The ram 16 ispivotally aflixed as by pin 19, to a plate 21 having a lug 22 extendingoutwardly therefrom. The plate 21 is permanently afiixed to the boom 12.

As hydraulic fluid under pressure is applied to the hydraulic actuator14, a piston housed internally of the cylinder 15 is moved and the ram'16 aflixed thereto also moves. As a result of the interconnectionbetween the pivot pins 17 and 19, the boom 12 is caused to pivot aboutthe pin 13 and raise or lower depending upon the manner in which thefluid under pressure is applied to the actuator 14. Such movement isindicated by the dashed line representations of the boom and the arrow20.

As shown by the base line 9 the post 11 of the portable crane 10 may beanchored in any manner desired. For example, provision may be made on adesired vehicle or in a loading platform for reception of the post .11.Preferably such receiving provisions are designed to permit the post 11to rotate and thus the boom 12 to swing to the desired position.

The boom -12 in accordance with the presently preferred embodiment ofthe present invention, is constructed of two channel members 23 and 24.A boom line hydraulic actuator illustrated generally at 25 includes acylinder 26 and a ram or shaft 27. The shaft 27 is affixed to a piston28 which is movably disposed internally of the cylinder 26, and moves inresponse to pressure under fluid being applied to the hydraulic actuator25. The cylinder 26 is affixed by way of pin 29 between the boom channelmembers 23 and 24. The pin 29 passes through a block 31 which is rigidlysecured to the end of the cylinder 26. A conduit 37 is interconnectedbetween the cylinder 26 and a source of fluid under pressure (not shown)which is housed within the post 11.

First pulley means including pulleys 32 and 33 are pivotally affixedabout a common axis, such as the pivot pin 34, at the terminal end ofthe boom 12. As is shown particularly in FIG. 3, spacers 35 hold thepulleys 32 and 33 apart, and also hold them spaced from the innersurfaces of the channel members 23 and 24, so that the pulleys 32 and 33are free to rotate without obstruction at all times.

Second pulley means including pulleys 40 and 41 are pivotally aflixedabout a common axis to the terminal end of the shaft 27, as for example,about the pivot 42. Typical shims or spacers 43 are used to space thepulleys from the shaft 27 thus causing them to be freely rotatable.

Guide means such as U shaped brackets 44 and 45 are carried by the shaft27 and in the presently preferred embodiment of the present invention,upon the pin 42, which secures the pulleys 40 and 41 to the shaft 27.The arms of the U shaped brackets 44 and 45 engage the flanges on thechannel members 23 and 24. By thus cooperatively engaging the channels,the guide brackets 44 and 45 maintain the two sets of pulleys in apredetermined alignment with respect to the boom 12. A cable engages theo) pulleys 32, 33, 40 and 41 and is secured at one end 51, preferably tothe channel 24 of the boom 12, thus maintaining one end of the cable orline 50 in a fixed relationship with respect to the boom -12. Theopposite end 52 of the cable 50 is free to move and for example, has ahook 53 attached thereto, which is particularly adapted for engagingloads.

A remote control switch 61 may be connected by means of line 62 to theapparatus housed within the post 11, which for example, would include amotor, a hydraulic pump, and a reservoir of hydraulic fluid. A pressuregauge 63 may be provided if such is desired, to determine the pressureappearing within the hydraulic system. Appropriate selector valves andbypass valves along with a relief valve would be interconnected with thehydraulic circuit as is well known in the art.

In operation, with no fluid under pressure applied to the system, theselector valve is placed in the desired position, an appropriate bypassvalve opened, and pressure then applied to the hook 53 in a downwarddirection. This pressure on the hook 53 is transmitted through the cable50 to the shaft 27 causing it to be pushed into the cylinder 26. Suchmovement of the shaft 27 carries the pulleys 40 and 41 toward thepulleys 32 and 33 as the end 52 of the cable 50 is withdrawn from theboom 12. The hook 53 is then engaged with the desired load and afterappropriate manipulation of the selector and bypass valves, fluid underpressure is applied to the system by starting the hydraulic pump andmotor, and pumping the fluid under pressure through the conduit 37 tothe cylinder 26. As the fluid under pressure enters the cylinder 26 thepiston 28 and the shaft 27 move away from the pulleys 32 and 33 and inso doing carry the pulleys 40 and 41. As this movement is accomplished,the end 52 of the cable 50 along with the hook 53 move in an upwarddirection as viewed in FIG. 1, and carries the load with it. The heightof the end of the boom 12 carrying the pulleys 32 and 33 is varied asdesired by applying fluid under pressure to the cylinder 15, causing theshaft 16 to move in or out as desired to lower or raise the end of theboom as above referred to.

As the pulleys 40 and 41 move toward or away from the pulleys 32 and 33,as a result of application of fluid under pressure to the cylinder 26 orthe removal thereof as above described, the guide brackets 44 and 45engage and slide along the channel members 23 and 24, thus at all timesmaintaining the pulleys 40 and 41 in a fixed relationship laterally withrespect to the channel members 23 and 24, but permit longitudinalmovement of the pulleys 40 and 41 with respect to the channel members 23and 24.

It should be noted that the utilization of the pulleys 32, 33, 40 and 41do not in any way ofifer a mechanical advantage in lifting any load thatmay be applied to the hook 53. The purpose of utilizing the pulley meansand hydraulic actuator as disclosed is to accomplish the desired resultof having a live line or cable that is engageable with loads for thepurpose of lifting or otherwise manipulating the same, and at the sametime having the capability of storing sufiicient cable within the systemto readily enable such lifting and manipulation from a de- 60 sireddistance. By utilizing the pulley means as disclosed wherein one of thepulley means is fixed and the other movable with respect thereto, suchstorage capacity is provided while at the same time permitting the loadto be lifted or otherwise manipulated directly with the free end of thelive cable housed upon the boom.

There has thus been disclosed a portable lifting apparatus which isrugged, inexpensive, compact and light in weight and which overcomes theprior art disadvantages of portable lifting apparatus.

What is claimed is:

A hydraulically powered portable lifting apparatus comprising:

(a) a rigid post member adapted at one end thereof to be pivotallymounted upon a support means for receiving the same;

(b) a rigid boom member attached at the opposite end of said post andadapted to be moved pivotally about said point of attachment with saidpost;

(c) boom lift means including a hydraulic actuator having one endthereof pivotally aflixed to said post and the opposite end thereofpivotally affixed to said rigid boom member intermediate the endsthereof,

( 1) said boom means being raised and lowered by actuation of saidhydraulic actuator;

(d) a first pair of pulleys pivotally mounted on a common axis adjacentthe opposite end of said boom in a fixed relationship with respect tosaid boom;

(e) a second hydraulic actuator, including a cylinder housing a movablepiston having a shaft aflixed thereto and extending through one end ofsaid cylinder;

(f) attaching means securing the other end of said cylinder to saidboom;

(g) a second pair of pulleys pivotally mounted on a common axis andsecured to the terminal end of said shaft and being movable with respectto said boom as said shaft moves upon application of fluid underpressure thereto;

(h) said cable being passed over said pulleys and having one end fixedwith respect to said boom and the other end free and extending from saidfirst pair of pulleys for lifting loads;

(i) means for applying fluid under pressure to said hydraulic actuatorthereby to cause said second pair of pulleys to move away from saidfirst pair of pulleys and said cable to move in a lifting direction inresponse to application of fluid under pressure to said actuator; and

(j) a pair of U shaped guide brackets atfixed to said terminal end ofsaid shaft and movable therewith,

( l) the arms of said brackets engaging said boom to retain said pairsof pulleys in aligned relationship with said boom.

References Cited by the Examiner UNITED STATES PATENTS 3,082,889 3/1963Bopp 212 X 3,129,821 4/1964 Graham et a1. 212- FOREIGN PATENTS 1,014,6666/1952 France.

149,326 12/ 1952 Sweden.

EVON C. BLUNK, Primary Examiner.

SAMUEL F. COLEMAN, Examiner.

A. L. LEVINE, Assistant Examiner.

